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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 13 |
| 3 | 218 |
| 4 | 4646 |
| 5 | 121080 |
| 6 | 3741144 |
| 7 | 133863792 |
| 8 | 5447294352 |
| 9 | 248518603584 |
| 10 | 12566268267840 |
| 11 | 697632464382336 |
| 12 | 42189230206182528 |
| 13 | 2760816706845539328 |
| 14 | 194381535085933095936 |
| 15 | 14652311175996819978240 |
| 16 | 1177370323796943823325184 |
| 17 | 100466288729505689717809152 |
[0,1,13,218,4646,121080,3741144,133863792, 5447294352,248518603584,12566268267840, 697632464382336,42189230206182528, 2760816706845539328,194381535085933095936, 14652311175996819978240,1177370323796943823325184, 100466288729505689717809152] |